One of Angel's most defining physical traits is a large tattoo behind his right shoulder. The tattoo depicts a griffin from the Book of Kells, with the addition of the letter "A" beneath it. According to Rupert Giles, the diary of a Watcher before him states the tattoo as a means of identifying him from other Vampires. However, when and where he received the tattoo has yet to be revealed.

Absences

The tattoo is not always present when Angel's back is seen, indicating that the makeup artists working on David Boreanaz did not always apply it, such as in the episode "Eternity".